Volume 3, Issue 6 August 2003

2003
2002
2001

Cooling Off California's Energy Crisis by David Pescovitz Printer-friendly version Professors Paul Wright (pictured) and Ed Arens are collaborating with PhD candidates Nathan Ota (ME) and Therese Pfeffer (Architecture) on the demand response energy system research. Bart Nagel photo As the summer temperature in California rises, so does the risk of brown outs. A spike in demand combined with the state's energy crisis means higher utility bills. To dramatically cut the cost of keeping cool, UC Berkeley researchers are developing a consumption-aware, cost-saving technology combining "demand response" energy pricing with a network of tiny sensors and smart thermostats for the home. "From June to September, there are huge peaks in our energy demand, " says mechanical engineering professor Paul Wright, a principal investigator on the project. "Air conditioning accounts for up to a 50 percent increase over baseline consumption. Wouldn't it be great if your thermostat and meter could receive information about when the price is lowest to run your air conditioner and adjust your thermostat to reflect that information?" Wright, Edward Arens, the director of UC Berkeley's Center for the Built Environment (CBE), and Cliff Federspiel, a researcher at the CBE, are building such a system with support from the California Energy Commission. The three are collaborating on the effort with professors David Auslander, Jan Rabaey, and others in the Berkeley Wireless Research Center, professor Richard White of the Berkeley Sensor and Actuator Center and his students, and a group led by professor David Culler, director of the Intel Research Berkeley laboratory. The multi-disciplinary project falls under the umbrella of the Center for Information Technology in the Interest of Society (CITRIS). The technological foundation for the system is a network of tiny wireless sensors that could be easily installed throughout a home. The sensors monitor temperatures in various parts of a house and relay that data back to a central computer for processing. The Berkeley researchers are developing the wireless sensors, including an "energy scavenging" technology that converts the ambient vibration of structural components like air-conditioning ducts into electricity. "The meter needs to know precisely when you use your electricity in order for the utility company to bill you based on the time of day," Wright says. Meanwhile, as energy prices shift throughout the day they would be transmitted wirelessly from the utility company to a smart meter at the home. The resident's only responsibility would be to program this or her temperature preferences on a user-friendly smart thermostat. Employing new control algorithms designed by the researchers, the system could then set the air conditioning system to match the desired temperature profile even as it changes throughout the day. Will smart thermostats help household consumers be more energy conscious? We want to hear from you... "Even if you're home during the day, there are ways to spread the thermal mass load of the house to keep it cool without turning on the air conditioner at peak times when the energy is most expensive," Wright says. Of course, the key to such a system is for the energy companies to create a demand response pricing structure for households. Wright is confident that once the "client-side" technology is proven, the utilities will oblige. "Big commercial buildings in the Bay Area already have time-of-use pricing on their meters," he says. "But the goal of this project is to diffuse it all the way into California homes." Paul Wright's Home Page Edward Arens's Home Page Center for the Built Environment Center for Information Technology Research in the Interest of Society (CITRIS) Berkeley Wireless Research Center Berkeley Sensor and Actuator Center Intel Research Berkeley Lab Notes is published online by the Public Affairs Office of the UC Berkeley College of Engineering. The Lab Notes mission is to illuminate groundbreaking research underway today at the College of Engineering that will dramatically change our lives tomorrow. Editor, Director of Public Affairs: Teresa Moore Writer, Researcher: David Pescovitz Designer: Michele Foley Subscribe or send comments to the Engineering Public Affairs Office: lab-notes@coe.berkeley.edu. © 2003 UC Regents. Updated 7/31/03.